Abstract: A low pass filter comprises a first series of transmission line elements connected between an input and an output; and a second series of shunt elements connected from the transmission line elements to a ground of the filter. At least one of the shunt elements has a distributed portion and a lumped portion. The distributed portion may comprise a tube mounted tangentially on a printed circuit board. The lumped portion may comprises a coil with a first lead connected to the first series of transmission line elements, and a second lead extending into the tube. A tuning element is moveably disposed in the tube. The tuning element may have an opening for receiving the second lead of the coil. The low pass filter may be used in a diplexer with one or more high pass filters. The diplexer may include power transmission apparatus.

Abstract: A distributed TEM resonator band pass filter has a set of rod-shaped resonators arranged in an interdigital line with alternate ones of the resonators being grounded to opposite walls of a housing. Each resonator has an ungrounded end which is capacitively coupled to a wall of the housing. Partitions, grounded to the housing, are located between successive ones of the resonators. Each partition closes off only a portion of the space between neighboring resonators to leave a coupling aperture. The interdigital arrangement provides for reduced loss and a higher Q. Input and output ports are provided at opposite ends of the interdigital line. The resonators may be constructed in the form of a suspended substrate, a stripline, or a microstrip configuration.

Abstract: A diplexer for use in communication of telephony and high-speed data transmission, including television, comprises two filters, each of which is constructed with plural stages in the form of a ladder network, one of the filters being a high-pass filter and the other of the filters being a low-pass filter. The filter components, inductors and capacitors, are located on one or opposed sides of a dielectric substrate. The filter components are arranged to minimize interference between signals traveling in the low-pass filter and the high-pass filter. In the case of a parallel branch of the ladder network in each of the filters, wherein the parallel branch comprises a resonant circuit of inductor and capacitor, the branches of the respective filters are located at opposite parts of the array of the filter components.

Abstract: A diplexer constructed on a stripline board includes a plurality of filters each having a series of filter sections providing an elongated physical configuration to the respective filter. Each filter section comprises an inductor and a capacitor. Each of the capacitors for each of the filters is formed in stripline format by laminating a pad of electrically conductive material to a sheet of electrically conductive material with the interposition of a layer of dielectric material between the pad and the sheet. Each inductor is formed as a coil wound about a core of air or solid magnetizable material. To provide for reduced physical size of the circuitry, thereby to accommodate emplacement of the circuitry within a television cable connection box, there is provided in a preferred embodiment of the invention filters of higher and lower frequency channels wherein the filter of the lower frequency channel has larger inductors.

Abstract: A detector circuit for radio-frequency signals is formed of a pair of matched diodes disposed on a common substrate which is heated by a temperature responsive feedback circuit to stabilize the temperature of the substrate and the diodes. A capacitor is connected to one or both of the diodes to form a detector of the detector circuit. A bias circuit provides equal bias currents to the two diodes, and an amplifier is connected to the two diodes to extract voltages associated with the bias currents, and to subtract these voltages in a differential manner so as to exclude the effect of bias voltage from an output signal of the amplifier. The amplifier is also coupled to an output terminal of the detector to isolate the detector from subsequent stages of signal processing, as well as to amplify detected signals. The diodes are each, preferably, Schottky diodes for improved dynamic range of signal detection.

Abstract: After a circuit is completely configured, including the mounting of semiconducting material onto a conductive layer and the connection of a conductor lead from a dot on the semiconducting material to the circuit, the required backdiode e/i characteristic is obtained by subjecting the whole circuit assembly to etching processing. The entire circuit is immersed into an electrolytic solution for etching away the semiconducting material to form the fragile narrow neck of the backdiode, thereby obtaining the required backdiode characteristic while advantageously obtaining an irreducible minimum of parasitic reactances associated with the resultant backdiode. Subsequent handling of the fragile backdiode as a component has been avoided because it is advantageously fabricated "in situ" pre-joined and integrated with the other components of the desired electronic circuit.